/**
 * Copyright (c) 2015-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

// This Webpack plugin ensures `npm install <library>` forces a project rebuild.
// We’re not sure why this isn't Webpack's default behavior.
// See https://github.com/facebook/create-react-app/issues/186.
// 暂时fix creat-react-app未完全接入webpack的fix
// webpack4 将missingDependencies和contextDependencies变为set类型，之前为数组，这里参照官方尚未发布的fix

'use strict'

class WatchMissingNodeModulesPlugin {
  constructor (nodeModulesPath) {
    this.nodeModulesPath = nodeModulesPath
  }

  apply (compiler) {
    compiler.hooks.emit.tap('WatchMissingNodeModulesPlugin', compilation => {
      var missingDeps = Array.from(compilation.missingDependencies)
      var nodeModulesPath = this.nodeModulesPath

      // If any missing files are expected to appear in node_modules...
      if (missingDeps.some(file => file.includes(nodeModulesPath))) {
        // ...tell webpack to watch node_modules recursively until they appear.
        compilation.contextDependencies.add(nodeModulesPath)
      }
    })
  }
}

module.exports = WatchMissingNodeModulesPlugin
